Vehicle rear suspension system

ABSTRACT

A rear suspension for a vehicle includes a knuckle for supporting a rear wheel of the vehicle, and the knuckle defines an opening. The rear suspension system further includes two suspension devices configured to be connected to the vehicle and an upper portion of the knuckle, such that each suspension device is oriented along an upright axis when the rear suspension system is mounted on the vehicle. In addition, the rear suspension system includes a control arm having a first portion configured to be connected to the vehicle and a second portion configured to extend between the axes of the suspension devices and into the opening of the knuckle when the rear suspension system is mounted on the vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Ser.No. 62/391,745 filed May 9, 2016, the disclosure of which is herebyincorporated in its entirety by reference herein.

TECHNICAL FIELD

The disclosure relates to a rear suspension system for use with avehicle.

BACKGROUND

Prior vehicle suspension systems are disclosed in U.S. Pat. No.6,357,769 and U.S. Patent Application Publication No. 2003/0098564.

SUMMARY

According to one aspect of the disclosure, a rear suspension system isprovided for a vehicle. The rear suspension system includes a knucklefor supporting a rear wheel of the vehicle, and the knuckle defines anopening. The rear suspension system further includes two suspensiondevices configured to be connected to the vehicle and an upper portionof the knuckle, such that each suspension device is oriented along anupright axis when the rear suspension system is mounted on the vehicle.In addition, the rear suspension system includes a control arm having afirst portion configured to be connected to the vehicle and a secondportion configured to extend between the axes of the suspension devicesand into the opening of the knuckle when the rear suspension system ismounted on the vehicle.

A vehicle according to the disclosure includes a vehicle supportstructure, first and second rear wheels that are each rotatable withrespect to the vehicle support structure, and first and secondindependent rear suspension systems associated with the first and secondrear wheels, respectively. Each rear suspension system includes aknuckle that supports one of the rear wheels, and the knuckle defines anopening. Each rear suspension system further includes two suspensiondevices connected to the vehicle support structure and an upper portionof the knuckle, such that each suspension device is oriented along anaxis, and a control arm having a first portion supported by the vehiclesupport structure and a second portion that extends between the axes andinto the opening of the knuckle.

According to yet another aspect of the disclosure, a rear suspensionsystem for a vehicle having a rear wheel and tire is provided. The rearsuspension system includes a knuckle for supporting the rear wheel,wherein an upper portion of the knuckle defines an opening. The rearsuspension system further includes an upper control arm and a lowercontrol arm. The upper control arm has a first portion configured to beconnected to the vehicle and a second portion configured to extend intothe opening of the knuckle and be connected to the upper portion of theknuckle at a first connection location. The lower control arm has afirst portion configured to be connected to the vehicle and a secondportion configured to be connected to a lower portion of the knuckle ata second connection location such that the first and second connectionlocations are generally vertically aligned with each other, when viewedin a longitudinal direction of the vehicle, and positioned proximate thetire of the vehicle when the rear suspension system is mounted on thevehicle.

While exemplary embodiments are illustrated and disclosed, suchdisclosure should not be construed to limit the claims. It isanticipated that various modifications and alternative designs may bemade without departing from the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vehicle according to the presentdisclosure;

FIG. 2 is a top view of a chassis assembly of the vehicle, whichincludes three axle pairs connected to six wheels and three dual motorgearbox assemblies according to the disclosure for driving the wheels,wherein each wheel may be a single wheel, such as at a front of thevehicle, or a double wheel pair, such as at a rear of the vehicle;

FIG. 3 is a bottom view of the chassis assembly showing front and rearsuspension systems according to the disclosure;

FIG. 4 is a perspective view of one of the motor gearbox assemblies,which includes an external housing;

FIG. 5 is a perspective view of the motor gearbox assembly of FIG. 4,with the housing removed to show first and second independent drivesystems, wherein each drive system includes an electric motor and anassociated gear train connected to the motor;

FIG. 6 is a perspective sectional view of the housing showing details ofa lubrication passage arrangement formed in the housing;

FIG. 7 is a fragmentary perspective view of the housing showing furtherdetails of the lubrication passage arrangement;

FIG. 8 is a fragmentary side perspective view of the housing showingfurther details of the lubrication passage arrangement;

FIG. 9 is a top view of the first and second drive systems of FIG. 5;

FIG. 10 is a perspective view of the first drive system of FIG. 9operating in a low gear ratio mode;

FIG. 11 is a perspective view of the first drive system of FIG. 9operating in a high gear ratio mode;

FIG. 12 is a front perspective view of a front portion of the vehicleshowing a front suspension system according to the present disclosure;

FIG. 13A is a side perspective view of the front portion of the vehicleshowing additional details of the front suspension system;

FIG. 13B is a fragmentary side view of the front portion of the vehicleshowing an air spring damper assembly and yoke mount of the frontsuspension system aligned with a front drive shaft;

FIG. 14 is a front perspective view of an alternate embodiment of thefront suspension system, showing various components of the frontsuspension system connected to a motor gearbox housing;

FIG. 15A is a bottom perspective view of a rear portion of the vehicleshowing a rear suspension system according to the present disclosure;

FIG. 15B is a perspective view of an upper suspension control arm of therear suspension system shown in FIG. 15A;

FIG. 16 is a side perspective view of the rear portion of the vehicleshowing additional details of the rear suspension system;

FIG. 17 is a rear end view of the vehicle showing a knuckle of the rearsuspension system and upper and lower suspension control arms connectedto the knuckle proximate a right rear tire;

FIG. 18 is a top perspective view of a rear end of the vehicle showingfurther details of the rear suspension system and a dual motor gearboxassembly positioned between two rear wheels and associated tires; and

FIG. 19 is a bottom perspective view of an alternate embodiment of therear suspension system, showing various components of the rearsuspension system connected to a motor gearbox housing.

DETAILED DESCRIPTION

As required, detailed embodiments are disclosed herein; however, it isto be understood that the disclosed embodiments are merely exemplary andthat various and alternative forms may be employed. The figures are notnecessarily to scale; some features may be exaggerated or minimized toshow details of particular components. Therefore, specific structuraland functional details disclosed herein are not to be interpreted aslimiting, but merely as a representative basis for teaching one skilledin the art.

A vehicle according to the present disclosure may be any suitablevehicle, such as a passenger car, truck, etc. FIG. 1 shows an exemplaryvehicle, which is an electric driven class 8 semi-truck 10 called theNIKOLA ONE™. In one embodiment, the truck 10 may be configured to pull atotal gross weight of 80,000 lbs. approximately 1,200 miles betweenstops, or even more than 1,200 miles between stops. The truck 10 shownin FIG. 1 has an aerodynamic cab 12, six rotatable wheels 14, and anelectric motor and associated gear train (e.g., gear train with dualgear reduction) at every wheel (6×6), which motors and gear trains maybe grouped in pairs to form a motor gearbox assembly as described belowin further detail. In the embodiment shown in FIG. 1, the four rearwheels 14 each include a dual wheel pair (two wheels that rotatetogether). In the embodiment shown in FIGS. 2 and 3, the rear wheels 14each include a relatively larger wheel and associated tire (e.g., supersingle wheel and tire). While each electric motor may be configured toproduce any suitable horsepower (HP), such as 100 to 400 HP, in oneembodiment each motor may be sized to produce 335 HP such that the truck10, with six motors combined, may output about 2,000 HP and over 3,700ft. lbs. of torque before gear reduction, and nearly 86,000 ft. lbs. ofinstant torque after gear reduction. The truck's six electric motors mayproduce superior horsepower, torque, acceleration, pulling and stoppingpower over other class 8 trucks currently on the road. The truck 10 mayfurther include an independent suspension system, such as a short/longarm (SLA) suspension system, for each of the six wheels 14 as describedbelow in further detail.

Referring to FIGS. 2 and 3, most of the truck's heavy components may bearranged to sit at or below a frame rail of frame 16 of chassis orvehicle support structure 17, thereby lowering the center of gravity byseveral feet and improving anti-roll over capabilities. This may also bepartially accomplished by removing the diesel engine and transmissionassociated with a typical class 8 truck, and manufacturing the cab 12out of lighter, but stronger carbon fiber panels, for example. Benefitsof removing the diesel engine may include a drastic reduction ingreenhouse gas emissions, a larger and more aerodynamic cab and asignificantly quieter ride. Furthermore, all an operator or driver mayneed to use to make the truck 10 go and stop may be an accelerator orelectric pedal and brake pedal (no shifting or clutches). The truck'ssimplified operation may open up the long haul market to a whole newgroup of drivers.

The truck's electric motors may be powered by any suitable energystorage system (ESS) 18, such as a rechargeable battery pack that may becharged in any suitable manner. For example, the ESS 18 may include aliquid cooled 320 kWh, lithium-ion battery pack (over 30,000 lithiumcells), which may be charged by an onboard turbine of a turbine assembly20. The turbine may automatically charge the batteries of the ESS 18when needed and eliminate the need to ever “plug-in.” The turbine mayproduce nearly 400 kW of clean energy, for example, which may provideample battery power to allow the truck 10 to climb a 6% grade at maximumweight at 65 MPH. When going downhill, the truck's six electric motorsmay be configured to absorb the braking energy normally lost and deliverit back to the batteries, thereby increasing component life, miles pergallon, safety, and freight efficiencies while eliminating noisy enginebrakes and reducing the potential for runaway trucks.

When compared to a typical class 8 diesel truck, the turbine of thetruck 10 may be much cleaner and more efficient. The turbine may also befuel agnostic, meaning it can run on gasoline, diesel or natural gas.

Because the above configuration includes an electric motor at each wheel14, the truck's control unit (described in further detail below) mayprovide dynamic control to each wheel 14. This may be referred to as“torque vectoring” and it is accomplished by controlling the speed andtorque of each of the six wheels 14 independent of each other at anygiven moment. Such a 6×6 torque vectoring control system may allow forsafer cornering, increased stopping power (e.g., doubled stoppingpower), improved traction, better tire wear and longer component lifeover current class 8 trucks.

The cab 12 of the truck 10 may be significantly larger than a typicalcab (e.g., 30% larger), yet may be more aerodynamic and have a lowercoefficient of drag than the typical cab (e.g., the co-efficient of dragmay be nearly 5% lower compared to current trucks on the market). Thecab 12 may also include various comfort and/or convenience features,such as a sliding mid-entry door for improved access and safety, a fullsize refrigerator and freezer, electric climate controlled cabin, touchscreen display (e.g., 15 inch touch screen display), 4G LTE internet,over the air software updates, panoramic windshield, sunroof, two fullsize beds, microwave and large screen television (e.g., 42 inchtelevision). All of these features may be powered by the ESS 18, therebyalleviating the need to idle or run a separate generator.

The truck's hardware and/or software may also be configured to providecompatibility with driverless vehicles in the future. Such technologymay allow a single driver to “virtually” hitch and lead up to 5driverless trucks 10 through a wireless vehicle network and self-drivingtechnology. This technology could solve the driver shortage andincreased freight costs facing the long haul transportation industry.

Motor Gearbox Description

Referring to FIGS. 2, 4 and 5, the electric motors mentioned above(which are identified with reference number 22 in FIG. 5) are grouped inpairs and each pair is mounted in a common motor gearbox housing 24along with an associated gear train 25 for each motor 22 to form a dualmotor gearbox assembly or dual motor gearbox 26. Each motor 22 andassociated gear train 25 may be referred to as a powertrain, driveassembly, or drive system 28. With the above configuration, a singlehousing 24 encloses or receives two independent electric motors 22 andassociated gear trains 25 that are capable of driving output wheels 14on opposite sides of the housing 24 at independent speeds and/ordirections. Furthermore, the housing 24 may be mounted on the frame 16or other portion of the vehicle support structure 17, such as a subframeor suspension cradle that is attached to the frame 16.

The above configuration of the dual motor gearbox 26 may provide asmaller overall volume for the electric powertrains by structurallysupporting the bearings, gears, electric motor rotor and stator, andshifting mechanism components in a smaller package designed to fitbetween opposite wheels 14, and associated wheel hubs on which thewheels 14 are mounted, of the truck 10 as shown in FIG. 2. The packagedesign and independent nature of the dual motor gearbox 26 eliminatesthe need for a differential and allows the output of the motors 22 to bedirectly coupled to the drive wheels 14 via half-shaft direct drivedrive-shafts. By eliminating large drive-shafts and differentials,greater mechanical efficiency may be achieved, and the truck 10 may bemade lighter.

This design also permits full independent suspension at each axlewithout some of the weight and mechanical complexity that would beincurred when using a typical drive-shaft differential combination andadapting such a combination for independent suspension. Front and rearindependent suspension systems according to the disclosure are explainedbelow in detail under the headings “Front Independent Suspension Design”and “Rear Independent Suspension Design,” respectively.

The two drive systems 28 of a particular motor gearbox 26 may becompletely separate from each other with the exception of a forced fluid(e.g., oil) cooling and lubrication system and the structural nature ofthe housing 24, which are shared. Referring to FIG. 4, the housing 24may have an inlet 29 proximate a top of the housing 24 for receivinglubricant (e.g., oil), which may be distributed over components withinthe housing 24 and then collected at or near a bottom portion of thehousing 24. The housing 24 may have various passages and openingsmachined or otherwise formed therein for routing lubricant to desiredlocations within the housing 24, as explained below in more detail. Thelubricant may exit the housing 24 through one or more outlets 30 andthen be routed through a cooling and filtration assembly 31 (shown inFIG. 3), which may include a cooling unit and filter, before beingreturned to the housing 24 through suitable passages or conduits.

Referring to FIGS. 6-8, additional details of an example configurationof the housing 24 for enabling or facilitating flow of lubricant areshown. Referring to FIG. 6, lubricant may flow from the inlet 29 througha main passage 32 to first and second passage arrangements 34 and 36,respectively, that supply lubricant to first and second motorreceptacles 38 and 40, respectively, which each receive a motor 22, andto first and second gear train receptacles 42 and 44 respectively, whicheach at least partially receive a gear train 25. The first and secondmotor receptacles 38 and 40, respectively, are located on first andsecond opposite sides, respectively, of a housing central wall 46, andthe first and second gear train receptacles 42 and 44, respectively, maybe at least partially located on opposite sides of the housing centralwall 46.

The second passage arrangement 36 will now be described in more detail,with the understanding that the first passage arrangement 34 may havethe same or similar configuration, but with an inverse orientation, orpartial inverse orientation, in a longitudinal direction (e.g., arearwardly extending passage of the second passage arrangement 36 maycorrespond to a counterpart forwardly extending passage of the firstpassage arrangement 34). The second passage arrangement 36 may includemultiple channels or passages formed in housing walls, and multipleopenings in the housing walls that allow the passages to providelubricant to one or both of the motors 22 in the motor receptacles 38and 40, and one or both of the gear trains 25 in the gear trainreceptacles 42 and 44. For example, the second passage arrangement 36may include a lateral passage 48 that connects to a Y-shapedlongitudinally extending manifold or passage 50. The Y-shaped passage 50feeds a downwardly extending channel or passage 52 that communicateswith the second gear train receptacle 44 through multiple openingsformed in one or more housing walls. In addition, the Y-shaped passage50 extends to another lateral passage 54, which communicates with thesecond motor receptacle 40 through one or more openings 56 formed in acurved housing wall 58 that at least partially defines the second motorreceptacle 40. Referring to FIG. 7, the Y-shaped passage 50, or anotherpassage in communication with lateral passage 48, may also feed aV-shaped longitudinally extending passage or manifold 60, whichcommunicates with the first gear train receptacle 42 located on thefirst side of the housing central wall 46 through one or more openings62 formed in the housing central wall 46, as shown in FIG. 8.Furthermore, the V-shaped manifold 60 may be covered by a plate 64 asshown in FIG. 4.

With the above configuration, each passage arrangement 34, 36 isconfigured to supply lubricant on both sides of the housing central wall46. In addition, each passage arrangement 34, 36 is configured to supplylubricant to one of the motors 22 and to at least a portion of each geartrain 25. Furthermore, lubricant may be moved through each passagearrangement 34, 36 by pressure and/or gravity to lubricate and/or coolthe motors 22 and associated gear trains 25.

Returning to FIG. 5, each of the gear trains 25 may include multiplegears that are configured to mesh together to transmit torque from arespective motor 22 to a respective wheel 14. Furthermore, each geartrain 25 may be capable of running at multiple (e.g., two) speeds, andthe gear trains 25 may have the components and capability to shiftbetween gear ratios independent of each other. For example, each geartrain 25 may include a suitable shift mechanism 72 that is controlled byan electronic control unit, which may be driven by or otherwise incommunication with a vehicle control unit (e.g, a computer). With theabove configuration, an automatic shifting event can be triggered foreach wheel separately to limit power reduction during shifting, asexplained below in further detail. The electronic control unit and/orthe vehicle control unit may also control the motors 22 and/or othercomponents of the motor gearbox 26.

Each of the above mentioned control units may include suitable hardwareand/or software, such as one or more processors (e.g., one or moremicroprocessors, microcontrollers and/or programmable digital signalprocessors) in communication with, or configured to communicate with,one or more storage devices or media including computer readable programinstructions that are executable by the one or more processors so thatthe control unit may perform particular algorithms represented by thefunctions and/or operations described herein. Each control unit mayalso, or instead, include one or more application specific integratedcircuits, programmable gate arrays or programmable array logic,programmable logic devices, or digital signal processors.

By packaging the motors 22 and gear trains 25 in a housing 24 that canfit between opposite wheels 14 of the truck 10, a similar arrangementcan be applied to each axle pair along the vehicle 10. This effectivelyreduces the power requirement of each individual motor 22 by dividingthe driving load between all of the motors. As result, several smallermotors with less mechanical losses can be used instead of a single largemotor with more losses. Furthermore, when combined with independentcontrol of these motors, unique control and performance gains are madeavailable.

Referring to FIG. 9, additional details of the powertrains or drivesystems 28 will now be described. FIG. 9 shows first and second drivesystems 28 a and 28 b, respectively, of a motor gearbox 26, with thehousing 24 removed. The first drive system 28 a includes first motor 22a and associated first gear train 25 a, and the second drive system 28 bincludes second motor 22 b and associated second gear train 25 b. Eachdrive system 28 a, 28 b also includes suitable inputs or connections 73a, 73 b for receiving electrical power (e.g., from the ESS 18) and/orcontrol signals, and for providing the electrical power and/or controlsignals to the associated motor 22 a, 22 b and/or shift mechanisms 72.In addition, the gear trains 25 a and 25 b may be positioned at leastpartially between the motors 22 a and 22 b. In the embodiment shown inFIG. 9, the gear trains 25 a and 25 b are entirely disposed laterallybetween the motors 22 a and 22 b. Furthermore, staggered dividing line74 approximately indicates general separation or division of the drivesystems 28 a and 28 b.

As shown in FIG. 9, at least portions of the drive systems 28 a, 28 bmay have generally inverse orientations in a longitudinal direction 75of the truck 10 and with respect to a laterally extending, central plane76 of the motor gearbox 26. In other words, at least a portion of onedrive system 28 a or 28 b may have a generally inverse orientation withrespect to at least a portion of the other drive system in thelongitudinal direction 75 of the truck 10. For example, the motors 22 aand 22 b may have generally inverse orientations with respect to eachother in the longitudinal direction 75, and/or portions or all of thegear trains 25 a and 25 b may have generally inverse orientations withrespect to each other in the longitudinal direction 75 (e.g., at least aportion of one gear train 25 a may have a generally inverse orientationwith respect to at least a corresponding portion of the other gear train25 b in the longitudinal direction 75). In the embodiment shown in FIG.9, the motors 22 a and 22 b are offset with respect to each other in thelongitudinal direction 75 and have generally inverse orientations withrespect to each other, and multiple gears of the first gear train 25 aeach have a generally inverse orientation with respect to acorresponding gear of the second gear train 25 b. In that regard, in theembodiment shown in FIG. 9, motor axis or central axis 77 a of motor 22a (e.g., the axis about which the rotor of motor 22 a is rotatable) islocated forward of central plane 76 by a distance d₁, while motor axisor central axis 77 b of motor 22 b (e.g., the axis about which the rotorof motor 22 b is rotatable) is located rearward of central plane 76 by adistance d₂. Likewise, an intermediate gear 78 a of gear train 25 a islocated forward of central plane 76, while a corresponding intermediategear 78 b of gear train 25 b is located rearward of central plane 76(e.g., the central plane 76 extends between the intermediate gears 78 aand 78 b). In the illustrated embodiment, intermediate gear 78 a isrotatable about a gear axis 79 a that is located forward of the centralplane 76 by a distance d₃, and intermediate gear 78 b is rotatable abouta gear axis 79 b that is located rearward of the central plane 76 by adistance d₄. Furthermore, in the embodiment shown in FIG. 9, distance d₁is equal to distance d₂, and distance d₃ is equal to distance d₄. Outputgears 80 a and 80 b of the gear trains 25 a and 25 b, however, may bealigned along the central plane 76, and may also be axially aligned sothat the corresponding wheels 14 can be axially aligned. Therefore, theoutput gears 80 a and 80 b may be aligned with each other, while theother corresponding components of the drive systems 28 a and 28 b may beoffset with respect to each other in the longitudinal direction 75. Insome embodiments, corresponding components of the drive systems 28 a and28 b may be offset with respect to each other, but spaced relative tothe central plane 76 by different distances.

As further shown in FIG. 9, some corresponding components of the geartrains 25 a and 25 b may be offset with respect to each other by greaterdistances in the longitudinal direction 75 than the motors 22 a and 22b. For example, in the embodiment shown in FIG. 9, the central axes 77 aand 77 b of the motors 22 a and 22 b are spaced apart by a firstdistance equal to the sum of d₁ and d₂, while the gear axes 79 a and 79b of the intermediate gears 78 a and 78 b are spaced apart by a seconddistance equal to the sum of d₃ and d₄, wherein the second distance isgreater than the first distance.

It should also be noted that each drive system 28 a and 28 b isconfigured to independently drive a wheel 14 that is located on the sameside of the truck 10 as the corresponding motor 22 a, 22 b when themotor gearbox 26 is mounted on the frame 16 or other portion of thevehicle support structure 17. Referring to FIG. 9, the first drivesystem 28 a is configured to drive a wheel 14 (not shown) positionedproximate motor 22 a and to the left of motor 22 a, while the seconddrive system 28 b is configured to drive a wheel 14 (not shown)positioned proximate motor 22 b and to the right of motor 22 b. In thatregard, output gear 80 a may be connected by a first drive shaft ordrive half-shaft (not shown) to a wheel 14 located to the left of themotor 22 a, and output gear 80 b may be connected by a second driveshaft or drive half-shaft (not shown) to a wheel 14 located to the rightof the motor 22 b.

As also shown in FIG. 9, the gear trains 25 a and 25 b may at leastpartially overlap each other in a lateral direction 81 of the truck 10(e.g., at least a portion of the gear train 25 a may overlap a least aportion of the gear train 25 b) so that the lateral width of the overallmotor gearbox 26 may be reduced. In other words, portions of the geartrains 25 a and 25 b may occupy a shared volume 82 within the housing24. For example, the intermediate gears 78 a and 78 b may at leastpartially laterally overlap each other. In the embodiment shown in FIG.9, the intermediate gears 78 a and 78 b fully overlap each other so thatthey are aligned in the longitudinal direction 75.

With the configuration described above, the motor gearbox 26 may have acompact design. As result, and as mentioned above, a motor gearbox 26according to the disclosure may be positioned at each axle of the truck10.

Motor Gearbox Control Capabilities

As mentioned above, the motor gearbox design according to the presentdisclosure enables each gear train 25 and associated output wheel 14 torun at multiple (e.g., two) gear ratios. The output gear ratio for eachdrive wheel 14 can effectively be shifted independently of all otherwheels 14. FIG. 10 shows the first drive system 28 a operating in a lowgear mode or low gear ratio mode with arrows indicating direction ofrotation of the rotor of the motor 22 a and gears of the gear train 25a, and FIG. 11 shows drive system 28 a operating in a high gear mode orhigh gear ratio mode with arrows indicating direction of rotation of therotor of the motor 22 a and gears of the gear train 25 a. The rotor ofthe motor 22 a may also be rotated in an opposite direction to thatshown in FIGS. 10 and 11 to thereby cause gears of the gear train 25 ato rotate in opposite directions compared to the directions shown inFIGS. 10 and 11. As mentioned above, the gear train 25 a may include asuitable shift mechanism 72 for shifting the gear train 25 a between thegear ratio modes. For example, the shift mechanism 72 may include abarrel cam 83 that is actuated by a rotary or linear actuator that maybe located at least partially external to the motor gearbox 26 andcontrolled by the above-mentioned electronic control unit. The barrelcam 83 may be rotated or otherwise moved to cause one or more shiftselector forks 84 to move linearly and thereby cause one or more doggears 85, 86 to engage or disengage adjacent gears in order to shift thegear train 25 a between the gear ratio modes.

In the low gear ratio mode shown in FIG. 10, the dog gear 85 is in anengaged condition and the dog gear 86 is in a disengaged condition.Furthermore, in the low gear ratio mode, rotation of the rotor of motor22 a in a first direction causes input gear 87 to likewise rotate in thefirst direction, and the input gear 87 engages (e.g., meshes with) firstintermediate or driven gear 88 and causes the first driven gear 88 torotate in a second direction opposite the first direction. Because thedog gear 85 is in the engaged condition, the first driven gear 88 causessecond intermediate or driven gear 89 to likewise rotate in the seconddirection. The second driven gear 89 engages (e.g., meshes with) thirdintermediate or driven gear 90 and causes the third driven gear 90 torotate in the first direction, and the third driven gear 90 engages(e.g., meshes with) the intermediate gear 78 a (which may also bereferred to as a driven gear, e.g., fourth driven gear) and causes theintermediate gear 78 a to rotate in the second direction. Theintermediate gear 78 a is coupled to a fifth intermediate or driven gear91 such that rotation of the intermediate gear 78 a in the seconddirection causes the fifth driven gear 91 to also rotate in the seconddirection. The fifth driven gear 91 engages (e.g., meshes with) theoutput gear 80 a and causes the output gear to rotate in the firstdirection.

In the high gear ratio mode shown in FIG. 11, the dog gear 85 is in adisengaged condition and the dog gear 86 is in an engaged condition.Furthermore, in the high gear ratio mode, rotation of the rotor of motor22 a in the first direction causes the input gear 87 to likewise rotatein the first direction. Because the dog gear 86 is in the engagedcondition, the input gear 87 causes sixth intermediate or driven gear 92to likewise rotate in the first direction. The sixth driven gear 92engages (e.g., meshes with) the intermediate gear 78 a (e.g., fourthdriven gear) and causes the intermediate gear 78 a to rotate in thesecond direction. The intermediate gear 78 a causes the fifth drivengear 91 to also rotate in the second direction as explained above, andthe fifth driven gear 91 engages (e.g., meshes with) the output gear 80a and causes the output gear to rotate in the first direction.

During a transmission shift on a typical vehicle, the total power of avehicle would need to be de-coupled from the transmission/drivetrainusing a clutch. This results in a momentary complete loss of powerduring this shifting event. With the independent shifting controlafforded by the motor gearbox design of the present disclosure, vehicleshifting events can be staggered among the independent gear trainsaround the vehicle. For example, where there are three motor gearboxes26 (one per axle) and six independent motors 22 (one per output wheel 14or dual wheel pair), the staggered shifting would allow one of these sixgear trains 25 to be shifted at a time and then sequentially through theother gear trains. This means that instead of a total loss of powerduring shifting, there would only be a ⅙th reduction in power at anygiven time during the shift event. As a result, there is constant power,although slightly reduced, as the truck 10 shifts. Furthermore, with theabove configuration, a shifting event can be controlled to be efficientand smooth, without the driver feeling it happen.

Vehicle electronic stability control (ECS), or traction control, mayalso be performed by braking or reducing power to wheels 14 to preventslipping and improve traction. With independent speed and torque controlof all wheels 14, it is possible to provide more torque to wheels 14that have traction and are maintaining speeds to prevent slipping ofother wheels 14. It is also possible to provide full torque vectoringduring turning or high-speed avoidance. This may provide greaterstability and cornering performance by distributing torque where it isneeded during these maneuvers.

Independent motor 22 to wheel 14 coupling as a result of this designalso allows independent regenerative braking or deceleration of thewheels 14. This means that braking force/torque could be distributedindependently to each of the wheels 14 using the wheel motors 22 asgenerators, which may provide power back to the battery or energystorage system (e.g., ESS 18). Furthermore, the motor gearboxes 26 couldbe controlled to provide regenerative braking and deceleration at ornear the friction limit of the tires of the truck 10. This may bepossible by using wheel speed and direction sensors that are embedded ineach motor gearbox 26 and sense the speed and/or direction of a gear ineach gear train 25 that is directly coupled to a particular wheel 14.For example, each drive system 28 a, 28 b of a motor gearbox 26 mayinclude a primary gear speed and direction sensor 93 positionedproximate the associated intermediate gear 78 a, 78 b (e.g., proximatean outer circumference of the intermediate gear and oriented generallytransverse to the associated axis), as well as a secondary gear speedsensor 94 that may be positioned on a side of the associatedintermediate gear 78 a, 78 b.

Front Independent Suspension Design

Referring to FIGS. 2, 3 and 12-13B, the truck 10 further includes frontindependent suspension systems 95 designed around the front motorgearbox 26 and drive half-shafts intended to drive the front wheels 14of the vehicle 10. Typical Class 8 trucks do not have front wheel drive,so a unique design was developed to allow driving, steering andindependent suspension. Furthermore, the front suspension systems 95 maybe designed to accommodate an air brake system (e.g., air disc brakesystem) that is used for braking the front wheels 14. The frontsuspension system 95 for one of the front wheels 14 is shown in FIGS.12-13B, with the understanding that the truck 10 may include the same orsimilar front suspension at the other front wheel 14.

Referring to FIG. 12, adding front wheel drive capability addscomplexity due to the number of moving components vying for the samespace near the front wheel 14. Such components may include air brakesystem components (e.g., an air brake chamber 96 and brake caliperassembly 97 that is actuated by the air brake chamber 96), a steeringarm or link 98 of a steering system for steering the front wheel, frontsuspension system components (e.g., upper and lower independentsuspension control arms 99 and 100, respectively) and a drive half-shaft102 and corresponding constant velocity (CV) joint, for example. Toallow those components to connect to or otherwise be associated with thefront wheel 14, a custom front support member or knuckle 104 wasdeveloped for the front suspension system 95. The knuckle 104 rotatablysupports the front wheel 14 and associated hub, and may serve as adirect or indirect connection or support area for various components(e.g., the knuckle 104 may be configured to support various components).For example, the steering arm 98 may be pivotally connected to theknuckle 104 in any suitable manner, such as with a knuckle mount thatincludes a pivot member (e.g., pivot ball) and a pivot bearing (e.g.,pivot socket). Likewise, the control arms 99 and 100 of the frontsuspension system 95 may each be pivotably connected to the knuckle 104in any suitable manner, such as with knuckle mounts that each include apivot member (e.g., pivot ball) and a pivot bearing (e.g., pivotsocket). As another example, the air brake chamber 96 may be mounted onthe knuckle 104 or on the brake caliper assembly 97, which may bemounted on the knuckle 104. Furthermore, referring to FIGS. 13A and 13B,the air brake chamber 96 may be mounted rearward of a center (e.g.,rotation axis 105) of the front wheel 14 and associated hub, andproximate or outwardly of an outer circumference of the front wheel 14,to avoid contact with the drive half-shaft 102 and CV boot 106 (whichcovers the CV joint), steering arm 98, and suspension control arms 99and 100 during all steering and suspension operational situations (e.g.,through full suspension travel and full steering travel of the frontwheel 14).

Referring to FIG. 13B, the air brake chamber 96 may also be mountedabove the rotation axis 105 of the front wheel 14 and associated hub.Likewise, the air brake chamber 96 may be mounted rearward of a verticalplane 107 that passes through the rotation axis 105 and a top portion ofthe front wheel 14, such that the air brake chamber 96 is mountedrearward of a top-center of the front wheel 14. For example, the airbrake chamber 96 may be mounted rearward of the vertical plane 107 suchthat a center point of the air brake chamber 96 is positioned at anangle in the range 10° to 90° (more particularly 30° to 75°) relative tothe vertical plane 107 and axis 105.

Referring to FIGS. 12-13B, the front suspension system 95 furtherincludes a unique support member or yoke mount 108 for attaching asuspension device, such as a gas (e.g., air) spring and damper assembly109, to the lower control arm 100. The spring and damper assembly orspring-damper assembly 109 may include a gas spring 110 (e.g., airspring) and a damper 112 axially aligned with and positioned beneath thegas spring 110. The yoke mount 108 includes first and second legs 113and 114, respectively, that are configured to receive the drivehalf-shaft 102 therebetween so that the spring-damper assembly 109 maybe positioned over the drive half-shaft 102 (e.g., axis of the drivehalf-shaft 102). With such a configuration, the drive half-shaft 102(e.g., axis of the drive half-shaft 102) may be aligned with a yokemount axis and spring-damper assembly axis in order to keep the drivehalf-shaft 102 and spring-damper assembly 109 in their ideal alignment,as shown in FIG. 13B. One of the legs (e.g., first leg 113) of the yokemount 108 may also be configured to extend between the drive half-shaft102 and the steering arm 98. While the yoke mount 108 may be connectedto the spring-damper assembly 109 in any suitable manner, in theembodiment shown in FIGS. 13A and 13B, the first and second legs 113 and114 are fixedly connected to the spring-damper assembly 109 at first andsecond spaced apart locations, respectively. Furthermore, the spring 110may be connected to the frame 16 or other portion of the vehicle supportstructure 17 (e.g., subframe or suspension cradle).

Alternatively, the above-mentioned suspension device may be any suitablesuspension device, such as a linear or non-linear dynamic suspensionmember. For example, the suspension device may include a coil spring, amagnetic suspension member and/or an electromagnetic suspension member.

The front suspension systems 95 are also configured to fit around thefront motor gearbox 26, which is centered within the suspension cradle.This makes it possible to have independent front suspensions while alsobeing able to directly drive left and right front wheels 14independently using the electric dual motor gearbox 26 located inbetween the front wheels 14. In the embodiment shown in FIG. 13A,inboard ends of the control arms 99, 100 may be pivotally connected tothe vehicle support structure 17 (e.g., suspension cradle or frame 16)proximate the motor gearbox 26 and the center of the truck 10.

In another embodiment, the housing 24 of the front motor gearbox 26 maybe connected to at least one of the control arms 99 and 100 of one orboth of the front suspension systems 95. In the embodiment shown in FIG.14, for example, front motor gearbox 26′ includes an enlarged housing24′ to which the control arms 99 and 100 of right and left frontsuspension systems 95 are connected. In the illustrated embodiment, eachof the right and left sides of an upper portion of the housing 24′ hastwo upper, laterally projecting portions 116 to which a particular uppercontrol arm 99 is pivotally connected. Furthermore, the housing 24′includes an enlarged lower portion 118, and each of the right and leftsides of the lower portion 118 has two lower, laterally projectingportions 120 to which a particular lower control arm 100 is pivotallyconnected. The housing 24′ may be connected to vehicle support structure17′ (e.g., front suspension cradle or frame 16) and may be made of asuitable material, such as metal (e.g, aluminum), carbon-reinforcedplastic or other composite material, etc., so that the housing 24′ maysupport the above components. With such a configuration, portions of thefront suspension cradle may be omitted, so that the overall vehicleweight may be reduced. In addition, the front suspension cradle may beintegrally formed with the housing 24′ (e.g., molded together), as shownin FIG. 14, to further reduce vehicle weight, or the suspension cradlemay be formed separately from the housing 24′ and attached to thehousing 24′.

Rear Independent Suspension Design

Referring to FIGS. 3 and 15A-18, the truck 10 further includes rearindependent suspension systems 122 and associated cradles that areconfigured to provide independent suspension at each rear wheel 14,while also allowing direct independent driving of the rear wheels 14using a dual motor gearbox 26 located between the wheels 14 at each oftwo rear axle locations. The rear suspension systems 122 may also beconfigured to enable accurate alignment (e.g., coaxial alignment) ofdrive half-shafts 102 r connected to each rear motor gearbox 26, so thatthe output gears 80 of each rear motor gearbox 26 may be coaxiallyaligned with corresponding rear wheels 14 when the drive half-shafts 102r are positioned in a horizontal orientation. With such a configuration,the rear suspension systems 122 may provide improved suspension traveland feel. The rear suspension system 122 for one of the rear wheels 14is shown in FIGS. 15A-16, with the understanding that the truck 10 mayinclude the same or similar rear suspension at each rear wheel 14.

Referring to FIGS. 15A-16, the rear suspension system 122 includes upperand lower control arms 124 and 126, respectively, that may be configuredto have inboard pivot points or axes located as close to the center ofthe truck 10 as possible (around an associated motor gearbox 26) toallow the most accurate suspension travel from full jounce to rebound(i.e., full up and down movement). Likewise, as explained below indetail, the control arms 124 and 126 may also be configured to haveoutboard pivot points or axes as close to an associated rear tire aspossible. In addition, the rear suspension system 122 may include one ormore suspension devices, such as gas suspension members or air springs128 that are each oriented along an upright axis 130 (e.g., centralaxis) and connected to the vehicle support structure 17 (e.g.,suspension cradle or frame 16). Alternatively, each suspension devicemay comprise any suitable suspension device, such as a linear ornon-linear dynamic suspension member. For example, each suspensiondevice may comprise a coil spring, a magnetic suspension member and/oran electromagnetic suspension member.

In the embodiment shown in FIGS. 15A-16, the upper control arm 124includes a first or inboard portion having two arms, and a second oroutboard portion formed as a single arm. Inboard ends of the uppercontrol arm 124 are each pivotally attached to the vehicle supportstructure 17 (e.g., suspension cradle or frame 16), such as with acradle mount 132 (e.g., pivot member or rod and pivot bearing), at alocation around the exterior of the motor gearbox 26 and proximate thecenter of the truck 10. The outboard portion of the upper control arm124 may pass between two air springs 128 and/or between the associatedupright axes 130 of the air springs 128. In the embodiment shown in FIG.16, the outboard portion of the upper control arm 124 is centeredbetween the upright axes 130 of the air springs 128. In addition, theoutboard portion of the upper control arm 124 extends into an opening134 in a rear support member or knuckle 136, to which the two airsprings 128 are mounted. The outboard portion further includes a singlewheel side end or outboard end that may be pivotally connected to theknuckle 136, such as with a knuckle mount 138 (e.g., pivot member or rodand pivot bearing), at a location proximate an outboard side of theknuckle 136 (e.g., as close to a corresponding rear wheel as possible).For example, the outboard end of the upper control arm 124 may bepivotally connected to an outboard face of the knuckle 136. As a moredetailed example, the outboard end of the upper control arm 124 may bepivotally connected to the knuckle 136 with a knuckle mount 138including a pivot member, such as a pivot rod, that is fixedly receivedin a channel or notch formed in the outboard face of the knuckle 136 andabout which the upper control arm 124 is pivotable.

The lower control arm 126 includes an inboard portion having two inboardends that are each pivotally attached to the vehicle support structure17 (e.g., suspension cradle or frame 16), such as with a cradle mount140 (e.g., pivot member or rod and pivot bearing), at a location beneaththe motor gearbox 26. In the embodiment shown in FIG. 15A, the cradlemounts 140 of the lower control arm 126 are located closer to the centerof the truck 10 than the cradle mounts 132 of the upper control arm 124.Such a configuration may provide improved suspension response, whilealso providing improved suspension travel. In addition, the lowercontrol arm 126 includes an outboard portion that may have two wheelside or outboard side connection locations that are each supported byand pivotally attached to the knuckle 136 (e.g., at a lower end of theknuckle 136), such as with a knuckle mount 142 (e.g., pivot member orrod and pivot bearing).

Referring to FIG. 15A, the knuckle 136 is also configured to rotatablysupport a rear wheel 14 (e.g., dual wheel pair). For example, theknuckle 136 may be attached to a wheel spindle 144 that supports a rearwheel 14 (e.g., the wheel spindle 144 may be attached to a hub on whichthe rear wheel 14 is mounted).

In the embodiment shown in FIG. 16, the knuckle 136 includes upper andlower portions 145 and 146, respectively. Furthermore, the knuckle 136may be made as a single piece or multiple pieces that are joinedtogether, such as by welding. The upper portion 145 of the knuckle 136may include support sections 148 that project outwardly with respect tothe lower portion 146, and the opening 134 formed in the knuckle 136 mayextend through a central portion of the upper portion 145 and betweenthe support sections 148. The configuration of the knuckle 136 enablestwo air springs 128, or other suspension devices, to be mounted to a topof the knuckle (e.g., the upper portion 145) and further allows thesecond portion of the upper control arm 124 to pass through a majorityor all of the knuckle 136 to the outside or outboard face of the knuckle136. In addition, the second portion of the upper control arm 124 may bealigned with a central vertical axis of the knuckle 136 and an axis ofthe wheel 14 and associated hub.

The rear suspension system 122 may further include one or more shockabsorbers or dampers 150 connected between the lower control arm 126 andthe vehicle support structure 17, such as the suspension cradle or frame16. In the embodiment shown in FIG. 16, the damper 150 is positionedrearward of the air springs 128 and knuckle 136.

With the above configuration, the rear suspension system 122 may handlesignificant loads, while maintaining a low profile. For example, the airsprings 128 may cooperate to effectively handle large loads, yet eachair spring 128 may be sized to fit between the frame rail of the frame16 and an associated rear tire. Furthermore, the upper control arm 124and knuckle 136 may cooperate to keep loads centered on the associatedrear drive half-shaft 102 r.

Referring to FIG. 17, outboard portions or ends of the upper and lowercontrol arms 124 and 126, respectively, may be pivotally connected tothe knuckle 136 proximate rear tire 152 and associated wheel 14. Forexample, the outboard ends of the control arms 124 and 126 may bepivotally connected to the knuckle 136 as close to the tire 152 aspossible (e.g., within 15 cm of an inboard face of the tire 152, or 10cm or less of the inboard face of the tire 152). Furthermore, connectionlocations (e.g., pivot point or pivot axis locations) of the outboardportions of the control arms 124 and 126 with the knuckle 136 may begenerally vertically aligned with each other, when viewed in thelongitudinal direction 75 of the truck 10. In other words, connectionlocations of the outboard portions of the control arms 124 and 126 withthe knuckle 136 may fall generally within a vertical plane 154 that isoriented in the longitudinal direction 75 of the truck 10. For example,the outboard side mount 138 of the upper control arm 124 may bevertically aligned with the outboard side mounts 142 of the lowercontrol arm 126, when viewed in the longitudinal direction 75, such thatthe outboard side mount 138 of the upper control arm 124 and theoutboard side mounts 142 of the lower control arm 126 are located in thevertical plane 154. With the above configuration of the knuckle 136 andcorresponding connections to the control arms 124 and 126, the tire 152and associated wheel 14 may be able to maintain close to a verticalorientation with respect to a road surface through the full travel rangeof the rear suspension system 122. As a result, the rear suspensionsystem 122 may provide improved tracking of the tire 152.

FIG. 18 shows the inboard portions or ends of the upper and lowercontrol arms 124 and 126, respectively, pivotally connected to thevehicle support structure 17 (e.g., suspension cradle or frame 16)proximate the center of the truck 10 and motor gearbox 26. In anotherembodiment, inboard portions or ends of one or both of the control arms124 and 126 of each rear suspension system 122 for a particular rearaxle may be pivotally connected to the housing 24 of the associatedmotor gearbox 26. In the embodiment shown in FIG. 19, for example, motorgearbox 26″ includes an enlarged housing 24″ to which the control arms124 and 126 of aligned rear suspension systems 122 are connected. In theillustrated embodiment, each of the right and left sides of an upperportion of the housing 24″ has two upper, laterally projecting portions156 to which a particular upper control arm 124 is pivotally connected.Furthermore, the housing 24″ includes an elongated lower portion 158 towhich the lower control arms 126 are pivotally connected. The housing24″ may be connected to vehicle support structure 17″ (e.g., suspensioncradle or frame 16) and may be made of a suitable material, such asmetal (e.g, aluminum), carbon-reinforced plastic or other compositematerial, etc., so that the housing 24″ may support the abovecomponents. With such a configuration, portions of the suspension cradlemay be omitted, so that the overall vehicle weight may be reduced. Inaddition, the suspension cradle may be integrally formed with thehousing 24″ (e.g., molded together) to further reduce vehicle weight, orthe suspension cradle may be formed separately from the housing 24″ andattached to the housing 24″.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms according to thedisclosure. The words used in the specification are words of descriptionrather than limitation, and it is understood that various changes may bemade without departing from the spirit and scope of the disclosure.Additionally, the features of various implementing embodiments may becombined to form further embodiments according to the disclosure.

What is claimed is:
 1. A rear suspension system for a vehicle, the rearsuspension system comprising: a knuckle for supporting a rear wheel ofthe vehicle, the knuckle defining an opening; two suspension devicesconfigured to be connected to the vehicle and an upper portion of theknuckle, such that each suspension device is oriented along an uprightaxis when the rear suspension system is mounted on the vehicle; and acontrol arm having a first portion configured to be connected to thevehicle and a second portion configured to extend between the axes ofthe suspension devices and into the opening of the knuckle when the rearsuspension system is mounted on the vehicle.
 2. The rear suspensionsystem of claim 1 wherein each suspension device comprises a gassuspension member.
 3. The rear suspension system of claim 2 wherein eachgas suspension member comprises an air spring.
 4. The rear suspensionsystem of claim 1 wherein the second portion of the control arm isconfigured to extend between the suspension devices when the rearsuspension system is mounted on the vehicle.
 5. The rear suspensionsystem of claim 1 wherein the opening extends through the knuckle, andthe second portion of the control arm is connectable to an outboard faceof the knuckle when the rear suspension system is mounted on thevehicle.
 6. The rear suspension system of claim 5 wherein the secondportion of the control arm is connectable to the knuckle with a pivotmember.
 7. The rear suspension system of claim 6 wherein the knuckle hasa notch formed in the outboard face, and the notch is configured toreceive the pivot member.
 8. The rear suspension system of claim 1wherein the control arm is an upper control arm, and the rear suspensionsystem further comprises a lower control arm having a first portionconfigured to be connected to the vehicle and a second portionconfigured to be connected to a lower end of the knuckle such thatconnection locations of the second portions of the control arms with theknuckle are generally vertically aligned with each other, when viewed ina longitudinal direction of the vehicle, and positioned proximate a tireof the vehicle when the rear suspension system is mounted on thevehicle.
 9. The rear suspension system of claim 8 wherein the vehicleincludes a motor gearbox assembly including a motor for driving the rearwheel, a gear train associated with the motor, and a housing thatreceives the motor and the gear train, and wherein at least one of thelower and upper control arms is attachable to the housing when the rearsuspension system is mounted on the vehicle.
 10. The rear suspensionsystem of claim 8 further comprising a damper member adapted to beconnected to the lower control arm and the vehicle.
 11. The rearsuspension system of claim 1 wherein the vehicle includes a motorgearbox assembly including a motor for driving the rear wheel, a geartrain associated with the motor, and a housing that receives the motorand the gear train, and wherein the control arm is attachable to thehousing when the rear suspension system is mounted on the vehicle.
 12. Avehicle comprising: a vehicle support structure; first and second rearwheels that are each rotatable with respect to the vehicle supportstructure; and first and second independent rear suspension systemsassociated with the first and second rear wheels, respectively, eachrear suspension system including: a knuckle that supports one of therear wheels, the knuckle defining an opening; two suspension devicesconnected to the vehicle support structure and an upper portion of theknuckle, such that each suspension device is oriented along an axis; anda control arm having a first portion supported by the vehicle supportstructure and a second portion that extends between the axes and intothe opening of the knuckle.
 13. The vehicle of claim 12 wherein eachsuspension device comprises a gas suspension member.
 14. The vehicle ofclaim 12 wherein, for each rear suspension system, the second portion ofthe control arm extends between the suspension devices.
 15. The vehicleof claim 12 further comprising first and second tires associated withthe first and second rear wheels, respectively, wherein the control armof each rear suspension system is an upper control arm, and each rearsuspension system further comprises a lower control arm having a firstportion connected to the vehicle support structure and a second portionconnected to a lower end of the knuckle such that, for each rearsuspension system, connection locations of the second portions of thecontrol arms with the knuckle are generally vertically aligned with eachother, when viewed in a longitudinal direction of the vehicle, andpositioned proximate one of the tires.
 16. The vehicle of claim 15further comprising a motor gearbox assembly including first and secondmotors for driving the first and second rear wheels, respectively, firstand second gear trains associated with the first and second motors,respectively, and a housing that is connected to the vehicle supportstructure and that receives the motors and the gear trains, and whereinat least one of the lower and upper control arms of each rear suspensionsystem is attached to the housing.
 17. The vehicle of claim 12 furthercomprising a motor gearbox assembly including first and second motorsfor driving the first and second rear wheels, respectively, first andsecond gear trains associated with the first and second motors,respectively, and a housing that is connected to the vehicle supportstructure and that receives the motors and the gear trains, and whereinthe control arm of each rear suspension system is attached to thehousing.
 18. A rear suspension system for a vehicle having a rear wheeland tire, the rear suspension system comprising: a knuckle forsupporting the rear wheel, an upper portion of the knuckle defining anopening; an upper control arm having a first portion configured to beconnected to the vehicle and a second portion configured to extend intothe opening of the knuckle and be connected to the upper portion of theknuckle at a first connection location; and a lower control arm having afirst portion configured to be connected to the vehicle and a secondportion configured to be connected to a lower portion of the knuckle ata second connection location such that the first and second connectionlocations are generally vertically aligned with each other, when viewedin a longitudinal direction of the vehicle, and positioned proximate thetire of the vehicle when the rear suspension system is mounted on thevehicle.
 19. The rear suspension system of claim 18 wherein the openingextends through the knuckle, and the second portion of the upper controlarm is connectable to an outboard face of the knuckle when the rearsuspension system is mounted on the vehicle.
 20. The rear suspensionsystem of claim 19 wherein the second portion of the upper control armis connectable to the knuckle with a pivot member, and the knuckle has anotch formed in the outboard face that is configured to receive thepivot member.